Archive For The “Tutorial” Category
One of the most recognizable and beloved map products of all time is the USGS 7.5′ quadrangle topographic map, commonly known as a ‘quad’. These maps have been available to buy in paper format for many years, and are considered a definitive reference by backcountry users, such as hikers, campers, and fishing enthusiasts. These maps […]
In Part 1 of this tutorial, I wrote about getting Linux to recognize and manage your Garmin GPS unit. Now that everything is set up, we can begin to explore how to make use of the GPS. Most of the work behind the scenes is made possible by the garmin_gps module, which is included by […]
Interacting with your hiking/personal Garmin GPS unit in Linux can be simple and rewarding. However, getting started takes a lot of work behind the scenes. This tutorial requires you to execute terminal commands and modify read-only files, so it is for intermediate to expert users only. Before beginning, make sure that the following packages are […]
One of the most exciting new features in ArcGIS 10 is the introduction of iterating tools in ModelBuilder. The ability to step through a list has always been a mainstay of programming and computer science, and has been readily accessible to any GIS programmer with a little Python or C# experience. In previous versions of […]
The hypsometric contour interval on the classic USGS quadrangle maps is 40 feet. Although it’s not a nice round number, I think it looks fantastic at that scale. It’s good at representing many different terrain types. Which is why USGS contours have become a bit of a standard for many GIS and cartographic applications. But […]
One source of data that I feel is under-utilized is the USGS Board of Geographic Names. The BGN is a (mostly) comprehensive list of definitive feature names, covering most of the United States. The features are organized by state, by county, and by feature type, and each one has a latitude and a longitude. The […]
If you ever get the opportunity to work with bathymetric data, you may encounter CARIS files. CARIS is an enterprise GIS suite that is well suited to marine and hydrographic applications. Many GIS offices don’t have access to CARIS, but that doesn’t mean the data is out of your reach. CARIS offers a free data […]
PostGIS is a wonderful suite of tools, which really anchors the open source web mapping toolkit. However, it doesn’t always integrate well with an ArcGIS desktop environment. One obvious source of conflict relates to projections – most of ArcGIS’s projections are infinitesimally different than their real world counterparts. As an example, consider the Washington North […]
In my previous post, “When Scale Bars Lie”, I mentioned the dangerous things that can happen when the map unit is not set correctly. As I explained, it can lead to abnormal values, which are often manifested in scale bars. This week, a friend of mine was using GIS to calculate the areas of some […]
Almost everyone on the net has had the opportunity to use one of the big four web mapping sites: Google Maps, Bing Maps, Yahoo! Maps, and OpenStreetMap. It’s possible to host a custom map on your own site using one of these services, as long as you have some programming experience. But it only takes […]
